Thomas bullitt dixon



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SHEETS-SHEET LHXON-` TELEGRAPH AND LIKE SIGNALING SKSTEM. APPUCATION FILED ri. 9. lane. 1,323,58L

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I. DIXON.`

,'ELEGRAPH AND L'IKE SIGNALING SYSTEM.

APPLICATION FILED Fia. 9, Iene.

1,823,581. r IIIIIIIIIQII IIQC. 1919 Z SHEETS-SHEET 2.

UNITED srnfrns ra'rnnr onirica.

THOMAS BUIILITT DIXON, F NEW YORK, N. Y.

TELEGRAPH AND 'LIKE SIGNALING SYSTEM.

Specification of Letters Patent.

Continuation of application lSerial No. 40.694, filed `Tuly 19, 1915. Patent No. 1,193,999. This application filed February 9. 1916.

Yoi'li` and State vof New York. have invenicdcertain new and useful liii1iioyements in 'Telegraph and like Signaling i Sysleiiis. of whiclithe following' is aspen-.ih-

cation. Y

`- .\'l invention relates to telegraph 21ml like signaling systems, and particularly to submarine oi' cable. telegraph systems, and coiiilirises a. method ot and means;whereby the disturbing and.signal-distorting effects,

' -15 experienced in traiisniission through long' cable lines. are counter-balanced. and where-4 liy a. condenser of greater capacity, than has been practicable heretofore. may be employed iu shun-t relation with respect to the coil 'of the receiving), galvanouietcr or other primary receiving instrument, and whereby the cable circuit may' be balanced for duplex operation more readily than heretofore.

In the-'high speed duplex operation ot submarine cable circuits much difficulty has been' experienced heretofore. due to the diilicnlty of obtaining' a suttciently'close balance between the main and artificial lilies, and

also to indue-tive disturbances, and earth currents (particularly in the shore end connections).V VariousI means have been employed heretofore for reducing suc-h difli- .cultics such as the shunt-ing' 'ot' the, receiving instrument lby condensers. find by inductive resistaiices (which are commonly termed, ,in t.liissense, viiiagrnetie shunts). So fares I -iin aware, none oi' these arrangements'.hare proved highly successful, one reason being,

4,0v that it'the capacity of the shouting 'condenser or condensers be sniiiciently high to obviate the harmful eiiects of the disturbances mentioned, there isa tendency to distortion of the signals i'nanifesting itself liietiy in the 46 form of an overthrow beyond-thel zero line.

For this reason it has not been practicable heretoforev to employ condenscrs of suiiciently large capacity shunted around the receiving instrument to eliminate to the de- 60 sired degree disturbances due tothe causes mentioned,

lt has been lfound convenient to use, in

coiiiicctioi'i with priiiiai'y cable receiving apparatus', sri-called "niagniiiers constituting secondary receiving instruments, themselves operated by the primary receiving instruments; which magnifici-s magnify the signals of tl i primary receiving instrument and there )y not only make the signals more legible, but permit a. higher speed of operation. I have. 'found that when such a magnifier, (and particularly a magnifier such as hereinafter described, and of my invention) has ,capacity of proper value, and preferably both capacity and inductance, each of proper value, shunted 'around it, the former harnitul effects of shunted capacity of high value employed in connection with the pri.

mary receiving instrument, are obviated; in other words, I have found that the capacity,- or both capacity and,` iuductance, shunted around the secondary' receiving instrument, neutralize, as to the secondary receiving instrumcnt, the otherwise disturbing overchronV77 effect of the high value capacity shunted around the primary receiving instrument. By the use of capacity, 0r capat-,ity and inductive resistance, shunted 'around the secondary receiving instrument, and particularly around a secondary receiving instrument or magnifier of the type herein described, it. is thus possible to use capacity, shouted around the primary receiving instrument, of very much higher value than itis practicable to use other wise; and indeed by this means e very satisfactory working balance can be obtained, tor high speed operation, under conditions which would substantially preciude the obtaining of a Working balance otherwise. In addition, the capacity and ,inductive resistance so shouted around the secondary receiving instrument tend to eliminate any remaining disturbances not eliminated by the condenser, or condenser and inductive resistance, in shunt relation with respect toitlie primary receiving instrument.

The magnifier or secondary receiving instrument in connection with which shunted capacity, or capacity and inductance, is eniploy'ed, as above' mentioned, preferably comprises one or more selenium cellsv or.'

Bio

equivalent radio-electro-sensitive devices the primary signal receiving device being provided with' a reflector or mirror operated by the moving velement of the primary receiving instrumentv referred to, such reiicctor or mirror arranged to reect a beam of light variably across the surface or surfaces or' the selenium. cell or cells or A equivalent device employed as aforesaid; such selenium cell .or cells or equivalent device being located .in a circuit influencing a siphon recorder or other suitable 'instrument constituting the'.

finalreceiving o'r recording orretransmitting element. The beam of lightso re- ,inent of the'beam of light eitherincreas-A ying or decreasingtheillumination of suoli v,Selenium cell or other device, and thereby varying its resistance or other electrical effect,and so producing a variation in the current which actuates the Siphon recorder or other receiving, recording or retransmitting apparatus.

@were o: ssudiagrammatieally various aragirenier-its,y mbodying my said invention. n sa1d draw'ings:

Figurel is a diagram showing 'the gal-l4 vanometer which operates the said reflector located in the cross wire of the well known Wheatstone bridge arrangement'of receiving circuits and instruments, the view also indicating the reflector, the selenium cells,A

andA the receiving instrument operated by those cells-` i Fig. 2 is a similar view showing the coil of the said galvanometer located in the cross wire of a secondary Wheatstone brid e, it4 self constituting the cross wire of a primary VVheatstone bridge;l the receiving' instru- -ment operated by the selenium vcells being -also shown in the lcrosslwire of-a further Wheatstone bridge.

Fig. 3 is. .a diagram showing what is known as thev magnetic bridge arrangement, the said galvanome'tercoil being bridged across between the main and artiticial lines.

.Fig. 4i is a diagram similar. to Fig. 1,.

but illustrating an alternative oi" preferred arrangement of the capacity 'in shunt relation with respect to the primary receiving instrument'.

' Fig. 5 is a diagrammatic view showing.

two opposing galvanomcter coils mounted in a magnetic field and connected to associated selenium cells 'nr such manner that as theillumination of one cell decreases and In the accompanying drawings I illustrate i -the illuminati-on of the other cell increases,

traces connecting the 'galvai'ioinetcr coil and' the reflector.

Fig. S shows a front elevation of the said galvanometer coil.

,Fig 9 shows a top view ot the galvanometer coil and reflector.

Referring Afirst to Fig. l: l indicates the incoming cable end,2 the artificial line, 3 and 4: condcnsers rconnn'only provided in the main and aitiicial'line, 5 the cross wire of the lVheatston'e bridge wherein the coil fi of the receiving',galvanometer :is located, and designates'capacity (a condenser oi' condensers) 'shunted 4around V that galvanometer coil 6, while 8 designatesinductive resistance, also shuntedrai'ound the coil 9 designates the usual receiving shunted condenser in the cross wire ofthe bridge. Suitable regulating non-inductive resistances are provided, as is customary.-

10 designates the usual transmitting apparatus connected to the apex of the bridge. 11` designates-the reflector actuated by thc galvanometer coil (3. 12..12 desimiate selenium cells to be actuated-by a light pencil orpencils projected upon them bythe re- Hector 11 and caused to sweep across them by the movements of that reflector, as mentioned above. 13 designates diagrammati-l cally .the receiving instrun'icnt operated by the selenium cell circuits (such receiving instrument 4being cusinmarily a Siphon rccorder though it may be sonic other suitable type of receiving'instrument) 14 designates 4capacity (a condenser or condensers) shunted around this receiving instrun'ient 13, and '15 designates inductive resistance likewise shllnted around -this receiving instrument.

For convenience in arranging the various instruments in the diagram, the reiiector 1l is not shown'directly opposite the selenium cells 1.2; but it will he undcrstoodthat in practice it will bc so arranged as to refiect a light beamfrom sonic suitable source upon 4those selenium cells'. I have indicated hatching, on the faces of those selenium cells, a light beam- 16, 'in what may'be considcrcd the noi-mal or rest position, suchlight beam illuminating both selenium cells partly, andilluminating neither cell completely. It4 will apparent that detiection of the light beam in either directionl '125 A will lincrease the illumination of one sele` 'nium cell, and decrease the illumination of i i i cells are shown in multiple branches of the circuit of the receiving instrument 13, with batteries 17 and 1S of opposite polarity, relatively, in such multiple branches. It will be' apparent that with selenium cells 1Q of equal resistance, and with the light beam 1G illuminating equal areas of both cells, the two batteries of said two cells neutralize each other; but that with any movement of' the light beam 1G from the position showin, with corresponding decreased resistance Vof one selenium cell, and increased resistance of the other selenium cell, due to the changed illumination of those 'cells consequent upon the movement of the light beam, there will be a current variation through the receiving instrument 13 vsubstantially equal to tivice the current variation which will occur if only .one of the selenium cells 12 and its corresponding battery were employed.; the action ofthe selenium cells lbeing cunnilative. v

I have found that by giving proper value to the capacity 14 (whichvalue depends cases, considerably greater than that of uponconditions. of each particular installation' and uponrc'onditions which may vary from time to time, such' value vbeing there-- fore determined for each particular installation,` from time to time, by trial and test, the value oflcapacityl being, in many capacity .7) a much 'higher' value can be .gwen to the capacity 7 than has been practicable heretofore, and thereby disturbances such as are due to imperfect balance of the artificial linewith respect to the main line, and to induction, earth currents, etc., are neutralized to such an extent that,` whereas without the capacity 14, the signals would be unreadable even at quite low speeds, yet with the capacity 14 together witha capacity 7 of the proper.value,.and an inductive resistance 8 of proper value, perfect signals may be produced at very high speeds; in fact, the disturbances mentioned are for all practical purposes eliminated.

Various arrangements of receiving circuits and apparatus are known andv cominonly` employed in connection with sub; marine cables.. Therefore I lhave thought it better. to .illustrate my present invention (comprising capacity 'and-inductive resistance shuntedv around the receiving instrument in connection with high capacity and inductiveresistance shunted around the coil of -the receiving' galvanometerv or other primary receiving instrument) in connection with two other t'ypicalreceiving circuit arrangements. Ot' course these three typical circuit arrangements which are illustrated in Figs. 1, 2 and 3 are not all the possible or known arrangements ofreceiving circuits; b utto illustrate my invention in connection with all known or possible arrangements of receiving circuits would he lmidcnsoinc; and I believe lhat from the illustration oi my invcntion iu connection with lhi'ce typical receiving circuitarrangements the. principles of my invention will be made clear to those skilled in the art, and the applicability ot' 70 my invention t0 still other receiving circuit arrangements will be uuu-lc clear.

In the. arrangement shown in Fig. 2 the coil t olf the receivingl galvanomctcr. is located within a secondariv llv'hcatstone bridge 75 comprising 'arms 1l). 30, 21 and 32, and a cross wire 2i-, arms l.) and 2Q containing capacity, and arms 2l) and 21 containing nouinductiveresistance, and the cross wire also containing resistance, there being an inductive. shunt around the coil in thisl cross wire; there also being a shuntcd condenser '25 in series.l with the secondary bridge. -l

have shown the receiving instrument 13 of the selenium cell circuits in another lheat- 8 stone bridge, comprising arms 2li, 27, QS and 29, and a cross wire 30, there. being capacity in arms 26 and Q9. and there being non-inductive resistance in arms 27 and 28; and there being a magnetic sh'unt 31 around the 90 receiving instrument 13. In this case also the capacity and inductauce of the selenium 'cell circuits ot' the instrument 13 coaet with the capacity and iuductancc employed in connection with the line'coil (3, to neutralize theI 95 disturbing effects mentioned and distortion of signals. The Aselenium cell circuits of Figs. 1 and 2 (by the selenium cell circuits I mean not only the circuit branches through the selenium cells themselves, but also Athe continuations of those circuit-s comprising in Fig. 1,' the receiving instrument 13, thc shunted condenser 1-1, and the inductive shunt 15, and comprising-in Fig. 2 the third VVheatstone bridge and the receiving in- 105.

strument 13, and its magnetic shunt 31') may be interchanged, since. either selenium cell circuitl arrangement of these. two figures is equally suitable for use with the line instrui'nent circuits shown in both of these 110 figures.

In Fig. 3 I have shown what is knownas the magnetic bridge arrangement wherein the receiving coil' 6 is bridged across between the main'line and artificial line and is shunt- 115 ed by capacity 7, the line and. artiieial-l` passing through opposing inductive resist! ance coils 3Q. and 33. I have shown in this figure the same selenium cell. circuits as in Fig. 1, but the selenium :l circuits of Fig. 2 1Z0 are equally suitable for the arrangemenlI shown in Fig. 3.

T he arrangement shown in Fig. 4 is similar to that shown in Fig. 1 except that the condenser 7 is in shunt with respect to the 125 coil 6 only, instead-of being in shunt also with the condenser 9 and the yresistance in the cross Wire 5 of the bridge. I have found duced by magnet poles 34 and each coil having usual an internal core 34h; the coils being mechanically connected and mounted to move together. One ofthc selenium cells 12 is connected to one of these i coils 34, the other selenium cell being connected to the other coil 34. Theeoils lare to be understood as wound oppositely, so tha't current of the saine direction flowing through both coils causes them te oppose each other as to rotation.y It will be. appar-` ent that, supposing the two coils to be perfectlybalanced', one against -the other, with the light beam-'1 6 in .Sonie definite, position,

movement of that light beam from such'position will increase the illumination ot enea of the 'selenium cells and will deci-ease correspondingly. the illumination' ot' the other seleniuincell, so decreasingilow through one of 'the-opposing coils "34,' and increasing the i'iow through lthe other ot' the two opposing coils 34 and so 'causing deflection of thosc "coilsy` The arrangementshown'in Fig. 5 has the advantage that neither eoil has any noticeable electrostatic infiuenceon the. other, whereas, in theca'se of differentially wound coils, each winding'oi the ditlereniial eoil has an electrostatic influence, upon the other coilf. The construction is also very simple and the connections easily made.. libere i considerable dilliculty in properly winding small dillirentialcoils, such as galvanoinetercoils, whereas there is no'corresponding diliculty in properly winding individual separate coils such as are employed in Fig. 5.

Obviously the apparatus above 'described' is applicable for reception of signals oi lilies operated in one direction only, and .in which thereln'e, there is no occasion for `use ot an artificial line and for obtaining a.

balance between the main-line and the artificial line. 4Fig. G shows my apparatus'arranged .tor reception ot' signals on 'a line nient being similar to th-it shown in Fig. 4

Vand requiring no detailed description in view`ol the description alreadygiven with reference to Figs. l and 2l; In reception ot' signalsv on lines operated in one direction only, my apparatus herein described has the saine advantages as to correcting distortion 'or overthrow due to higlreapaeity employedin connection Withfthe primary receiving apparatus as it'lias in the vorrangements above described for duplex working. Als-o, e5

reasons, a much higher speed of loperation is obtainable in onedirection working, as Well .as in duplex working.

In order that the relation of the receiving,galvanomeler coil (i with reference to its reflector' ll ma)v be evident from the draw- `75 ings attached to .this specification l have shown such arrangement diagianimatically in Figs. 7, S and i); the coil (i having a liber suspension, the reflector ll havingA also a fiber Suspension, the coil and the reliector ge being connected by traces 37, these traces being connected to the coil 6 by a spreader 3H oi greater lengththan the spreader il!) which connects said traces tothe retlec- `tor; the resultbeing that the angular movevments of the i'eliector 1l are very much greater than the corresponding angular movements of the coil 6.

It has -been suggested heretofore to employ inductive, resistance in connection with selenium cells, 'to overcome the lag or inertia ot' those cells. l t should be understood that in arrangements such as shown in' Figs. l`t imzlusi've the inductive resistance einployed in shunt rela-tion to the instrument 95, 'operated by the selenium ,cells has no relation whatever 'te any lag or inertia of such selenium cells; there 'being no lag when the illumination of the selenium cells is sulii ciently intense, as explained hereafter; but 10o the action ol such inductive resistance. and the action ot' the condenser ll also in shunt relation to both the inductive resistance and the selenium cells, mutually ,modify each other to ih eend thattogether, when properly adjusted'. the)1 overcome t-he effects 0t`- signal distortion due to high capacity and indnctance in shunt relation to .the receiving galvanometer coil- G. This I have deL l termined in actual practice; and, without limiting myself to any particular theory as to such interact-imi, the probableexplanation is as follows (refer-ene being made toliig. 1, though the action in the other iig nres is similar) Supposing a current .Wave

to come in through the line cable circuit 1. This causes a flow of current through the.- receiving galvanonieter coil 6 and also causes condenser 7 and. inductive resistance 8 to charge. The resulting movement of the 12e coil 6 causes the beam of light playing upon selenium cells 12 Vto move, thereby causing flow of current through secondary receiving instrument 13 and causing condenser 14 and inductive resistance'l to charge. `As this 125 charging (1'. c., niagnetizationof the core) ol the inductiv'eresistance S increases, the resistance l(at first very high) which that tive resistance 1& has not yet risen to 'the' the resistance which it offers to lthe'floiv of current decreases, at a much slower relative rate than is true of inductlve resistance 8.

As the cable current dies down the condenser 2' begins to discharge both through the coil 6 and through the inductivc-.resist ance 8 in the samedirection as that of the cable current, the inductive resistance 8 now offering relatively small opposition to the flow of the discharge current of condenser 7, since the Acore of that inductive resistance 8 is now-wellmagnetized. As the discharge of condenserl 7 decreases the inductive resistance. 8 discharges, such discharge taking place through the coil 6in a direction opposite to thatof the `cable current so as to tend to cause that coil to return or swing back toward the zero position, and the higherV the capacityvalue of condenser `7 the greater will be4 the current iiiow throughy inductive resistance 8. and the,` resultant discharge of 'that inductive 'resistance tending to return the coil 6 to, or beyond, z ero; from which ma be seen why the overthrow of a coilas 6 may result, as is observed when suc capacity beyond a certain value is used in shuntrelation to the coll. The condenser 14,

.discharging throughsecondary receiving instrument 13 and inductive resistance l5 in parallel, discharges through its. receiving instrument 13 following the discharge of in ductive resistance' through coil 6 as before stated; and the condenser 14 discharges through. its instrument 13 at a considerable rate, though also discharging through its inductive resistance 15 o vging to the fact thatishe magnetization ofi" e core of inducsamerelative degree of saturation as did il@ core of inductive resistance 8 prior vto the discharge of that inductive resistance 8 as above stated; the-relatively slower rise of magnetization of the core of inductive resistance 15 being due to vthe relativel high ohmic resistance in series with that in uctive resistance. The discharge from condenser 14 is in a direction tending to hold the coil 34 of instrument 13 against return, and 'thus this discharge of condenser 14 through instrument 13 tends to neutralize the overthrow of coil 6 so far as the recording or reproduction of signals by instrument 13 is concerned.

Y1? proper adjustment of the capacity of con enrl, of the inductance of inductive wasser a resistance 15, and of the resistance of the olnnic resistance in series with inductive resistance l5, any desired conipeusation for the citent of high capacit); 7 in shunt with coil muy be obtained.

".lhc radio-clcetro-scusitire devices em plcved as above described nrc iiot necessarily .selenium rolls the)v may be actinium cells, aci-lullin; having a relatively low resistance in (.larli'uoss and a relatively high resistance when brightly illuminated; also tlicrmal couples or lthermo-piles may be used, .since such devices will generate current variably if acted upon variably by heat rays, and heat rays may be reflected variably just as light rays arc reflected variably.

This application is a continuation of my application Serial No, 40,694 filed July 19, 1915, now Patent No. 1,193,999, dated Au-4 gust 8, 1916, wherein is disclosed a method of cn'iploying a large number of light beams derived either from a single source or from a plurality of sources, such light beams being concentrated in the first instance upon a primary actuating device reflector, and then being reconceutruted with substantial coincidence uponthe radio-electro-sensitive dev vice or devicescmployed. thereby affording a very intense illumination of such radioelcctro-sensitive devices. So far as the so` .called lag elfect of selenium cells is concerned, which lag effect has been referred to hcrcinbeforc, my experience is that when the illumination of the radio-electrosensitive devices is sufficiently intenso, as is theca se when the multiple light beam arrange ment of my said prior application is employed, there is no observable lag, and therefore no need of compensation for lag by inductive resistance in shunt relation to the receiving instrument operated-by the radio-electro-sensitive devices.

llfhat I claim is:

1. In. a telegraph system siicli"'as described the combination with amain line,

'.'aces of such device or devices Aby the action of such reflector, a' circuit for such device or de rices comprising receiving instrument arranged to be actuated by the variation of such device or devices due to varying action ot a beam of radiant energy thereon, and capacity in shunt relation with respect to such receiving. instrument.

2. In a telegraph lsystem such as described, the combination with a main line,

. vice or dei lees by the action of such rescribed, the combination with a mainline, an

Hector, a circuit forsuchdevice or devices comprising a receiving instrument arranged to be actuatedby the variation of such device or devices due to varying action of a Abeam of radiant energy thereon, and capacity in shunt relationwith respect to such receiving instrument.

3. In a' telegraph system such as described, the` combination 4with a main line, anartificial line, and signal receiving and transmitting circuits therefor. comprising" a receiving instrument comprising an actuating coiljand a reiector which thahceil actuate's, andcapacity in shunt relation with respect to such coil, of 'one or more radio-l clectro-sensitive devices arranged to be acted upon by a beam of radiantvenergy caused to move across. the surface or surfaces of such device or devices by the actionof such relector, a circuit for such device or devices comprising a receiving instrument arranged to be actuated by the variation of such device or devices due to varying action of'a beam of radiant energy thereon, and capacity and \in ductive resistance in' shunt relation with respect to such .receiving instrument.

4. In aV telegraph system v,suchv as deartificial line, and signal receiving and transmitting circuits therefor .comprising a receiving instrument comprising an actuating coil an'd a reflector which that coil actuates, and capacity and inductive resistance in shunt relation. with respect to such coil, of one or more radioeelcctro-sensitive devices arranged to be a'cted upon bv a beam of radiant energy caused to inbve across'the surface or surfaces of,4 such de-' vice or devices by the action .of such re- Hector, a circuit for such device or devices J comprising a receiving instrument arranged to be actuated by the variation of the rcsistanee or such cell or cells due to varying action ot a beam of `radiant energy thereon,

and capacity and inductive resistance in shunt relation with respect to .such receiving instrument.

5. In a telegraph system such as de'- scribed, the combination with a main line, an artificial line, and signal receiving and transmitting circuits therefor comprising a'` primary receiving instrument 'and a 'secondary receiving instrument operated by that primary iceeiving instrument, the priniary'receiving instrument having capacity in shunt relation. with respect to it, the secondary receiving instrument having alsor capacityI in shunt 4relation .with it, the arrange'i'nent being such that the capacityl in shunt relation withrespect to the second! ary receiving instrument; permits a lai-ge capacity in shunt relation with respec-l vto the primary4 receiving instrument and tends to eliminate disturbances and' permits higher speed of operation.

6. In a telegraph system such as describedv the combination with a main line, an arti.

'ici'alline, and signal receiving andftra'iismitting 'circuits therefor comprising a pri# mary receiving instrument, and a secondary receiving instru-nient operated by that \piimary receiving instrument, the primary receiving instrument having capacity and inductive resistance .in shimt'relation with re-v spect to it, the secondary receiving instrument having also capacity in, shunt relation with it, the arrangement being such tliat'the capacity in shunt relation with respect to the secondary receiving instrumentpermits a large capacity and an inductive resistance in shunt relation with respect to; theA primary receiving instrument 'and tends to eliminate disturbances and permit higher speed of operation. A i

In a telegraph system such as described, the combination with a main-linega-n artificialvlineiand signal receiving. and trans- ,mittingcircuits therefor comprisingza rimaryreceiving instrument and a secon ary v receiving instrument operated by that pri- A ,mary receiving instrument, the primar re` ceiving instrument having capacity in s unt relation "with respect toit, the secondary. receiving instrument havingr also capacity and inductive resistance in shunt relation with it. thearrangcim-,nt being` such that the :capacity and inductive resistance in shunt relation with respect to the secondary re- 4 ceiving,'instrument'permits a large capacity in shunt ijelatioiiwith respect to the primary receiving instrument and tends to eliminate disturbances and permit-s higher speed of operation. v l

S.A In atelegrapli system such as described,

the combination with a main lnenan arti- .ticial line, fand signal receiving and transmitting circuits therefor comprising a primary receiving instrument and a 'secondary receiving instrument 'operated by that prifv` 'mary receiving instrument, the primary rc-A ccivinginstrument having capacity and inductive Aresistance in inspect to it, the secondary receiving instru- .ment having also capacity and' inductive 115- iiov shunt relation with I,

sistancc in shunt relation with it, the' arrangement being such that the capacity and inductive resistance in shunt relation with,

respect to the secondary receiving instrument permits a large capacity and aninductire resistance in shunt relation with res )ect to the primary receiving instrument and' .that primary receiving instrument, thereby permitting high capacity to be employed in shunt relation with respect to the primary signal-receiving instrument, without accompanying material distortion of -signals.

10. The herein described iucthodof neutralizing signal-distorting effects of high capacity and induct-a-nce in shunt relation to the primary receiving instrument ofatele- `graph system such as described, which cony sists in neutralizing the/said signal-distorting etl'ect of high capacity and inductancein such shunt relation to the primarv signalrcceiving instrument by the action vof capacity and inductive resistance iii-shunt relation to a secondary receiving instrument. operated by that primary receiving instrument, thereby permitting highcapacity and inductive resistance to be employed in shuntrelation with respect tothe primary signalreceii'ing instrument, `Without accompanying material distortion o'E signals.

'11. The herein described method of neutralizing signal distortin` capacity and indnctance both in shunt relation to thcvv primary receiving instrument of a telcgraiph system such as described,

which consists in neutralizing by the 'discharge current, of capacity in shunt relation to a secondary receiving instrument operated by that primary receiving instrument` the signal-distorting effec-t of the charge/'and discharge through the primary receiving instrumentot the indnctance in shunt .relation to that primary receiving instrument.

12. In a telegraph .system such .described the combination oi' a inovably mounted coil having two differential Windings two selenium cells connected the one to om` such winding-the other'tothe other such winding in such manner that increase ot' current, flow through one-'such winding and decreasc'ot current floivtlirough the other such winding tend to cause ii'rn'enient of the coil in the same direction` ngans for moving a beam of light across the surfaces of said cells jointly, and in such manner that as the .area of surface illuminated of g effects of high one such cell increases, the area ot the surtace illuminated ot the other such cell decreases, and capacity in shunt relation to each such winding.

'13. In a telegraph the combination ot coils connected to more together and located in a magnetic field', two radio-cloctroseiisitii'e devices connected thc one to one such winding' and thc other to the other such winding in such manner 'that with current flowing in the saine direction through both coils said coils oppose one another as to rctation, and means for moving a beam of' radiant energy across the surfaces of said radio-electro-sensitive devices jointly in vstexn such as described -such manner that as the area ci' surface of one such radio-electro-sensitive device exposed to suoli beam increases, the area of the other*radio-electrossensitive device so eX- posedto said beam decreases.

' 14'. In atelegraph System such as described the combination of two inovably mounted coils connected to move together and located in a magnetic field` two radio-electro-sensi tiye devices' connected the one to one such Winding and the other to the other such winding in such manner that with current flowing in thefsaiiie direction through both coils said coils oppose one another as to rotation, andmeans for moving a beam of radiantv energy across the surfaces of said radio electro sensitive devices jointly in Asuch manner that as the area oi surface of one such radio-electro-scnsitive device eX- posed to such beam increases, the arca of the otherV radio-electro-sensitive device se exposed to said beam dccrea ses, and. ca for each coil in shunt relation to suc coil.. '153 In atelegraph system such as described the combination of tivo movably mounted coils connected to move together and located in a magnetic held, two radio-elcetro-sensin tive devices connected the one to one such Winding and the other to the other suoli Winding in such manner that with current flowing inthe same direction through both coils said coils oppose one another as to rota tionhandmeans for movi-ng a beam of radiant, energy across the surfaces ot said radio-electrsensitive devices iointly in such manner that. as the area of siu'face of one such radio-electro-sensitive device exposed to such beam increases, the area 'of the other radio#electro-sensitive device so exposed to said beam' decreases, and capacity and inductance for .each coil in shunt relation to such coil. f i

16. In a telegraph system such as described the combination of two niev'ably mounted coils connected to move together and located in a magnetic field, 'tivo radio-electrosensitive devices connected the one to one such Winding and the other to the other two movably mounted acity,

gosed to such beam increases, the area of the other radio-electroesonsitive device so eX- posed to said beam decreases, and induetance for each coil in shunt relation to sncli coil. I

In testimony whereof I have signed thisv specification in the presence of two subscrib- -ing witnesses.

' THOMAS BULLIT'I DIXON, l Witnesses:

' H. M. MARBLE,

PAUL H. FRANKE. 

